(from Audi
Press Release) Distinct sports
appeal and supreme comfort – these are the two defining
characteristics of the Audi A8. At the time of its market launch
three years ago, this large saloon shot straight to the top of the
luxury segment thanks to its dynamic qualities. The brand with the
four-ring emblem is now unveiling a sporty top model of the very
highest calibre in the luxury segment: the new Audi S8. It will be
appearing on the market in the mid of 2006, with a price tag of EUR
97,600.

The Audi S8 is equipped with a new V10 engine that capitalises on
the expertise of the super sports car Lamborghini Gallardo. The
10-cylinder power unit develops 450 bhp of power and 540 Nm of
torque from a swept volume of 5.2 litres. The torque value is
achieved at as low an engine speed as 3,500 rpm. As on the Le Mans
winning R8, the most successful racing car in the world, FSI petrol
direct injection assures superior power output in the Audi S8. This
luxury saloon sprints from 0 to 100 km/h in 5.1 seconds, and is
electronically governed at 250 km/h.

The driveline and chassis of the S8 have been modified to reflect
the engine's power. A quattro drivetrain of the latest generation
with asymmetric/dynamic torque distribution diverts the engine's
power to all four wheels. The firmer settings of the adaptive air
suspension sport and modifications to the steering ensure that the
power and dynamism of the drivetrain are translated with precision
into locomotion.

The design of the new S8 completes the picture – the sporty top
model also has the looks of the most athletic luxury saloon car.
There is an atmosphere of luxurious elegance inside the car. Its
lavish equipment lends the Audi S8 a pre-eminent status within the
competitive field.

Engine: New V10 with FSI technology adopted
from the world of motor racing

In outfitting the S8
with the V10, Audi is introducing an engine technology that has long
been demonstrating its performance potential in the world of Formula
1 racing. The Italian super sports car brand Lamborghini, a
subsidiary of Audi, likewise regards the ten-cylinder engine as
synonymous with dynamic power. This engine concept has a much more
sporty emphasis than a comparable twelve-cylinder power unit.
Ten-cylinder engines are more compact and lighter; thanks to the
smaller number of components, they have lower moving masses and less
internal friction.

The 450 bhp V10 is the second generation of Audi V-engines, all with
a 90-degree included angle and a spacing of 90 millimetres between
cylinder centres. Key areas of the Audi version have been
reengineered compared with the engine in the Lamborghini Gallardo.
The bore has been increased from 82.5 to 84.5 mm; the stroke is 92.8
mm and the displacement 5204 cm3. A so-called bedplate structure –
an intermediate frame – reinforces the extremely compact crankcase,
which is made from cast aluminium.

With its crankpin offset of 18 degrees, the V10 fires at the ideal
spacing of 72 degrees crankshaft angle. A balancing shaft located
within the "vee" eliminates the so-called free inertial forces of
the first degree and also contributes towards the engine's notable
refinement. All four camshafts can be adjusted continuously by 42
degrees crankshaft angle, depending on load and engine speed, to
optimise filling of the combustion chambers and thus enhance the
power output. They are driven by no-maintenance chains and actuate
the 40 valves via roller cam followers.

The V10 in the new Audi S8 uses FSI petrol direct injection. This
permits a high compression ratio of 12.5:1 and a correspondingly
more effective combustion process based on a lambda value of 1. The
common rail injection system delivers the fuel directly to the
combustion chambers in precisely metered amounts, at a pressure of
up to 100 bar.

The two-stage magnesium variable intake manifold incorporates
electronically controlled tumble flaps that induce a swirling
movement in the air drawn in. Four close-coupled main catalytic
converters take charge of exhaust emission control for the V10 of
the Audi S8. FSI technology has impressively demonstrated its
potential in motor sport – the R8 racing car equipped with it
participated in the
Le Mans 24 Hours on five occasions for Audi, winning the race on
four of those occasions.

The powerful ten-cylinder engine is designed for impressive torque
as well as engine power. It generates 450 bhp at 7,000 rpm, but
musters up 540 Nm of torque at just 3,500 rpm. 90 percent of the
torque is available from as low as 2,300 rpm. The V10 exhibits
spontaneous throttle response and very refined running, and under
load it also produces sonorous acoustics, as befits a dynamic car.

The V10 imparts the luxury saloon with the road performance of a
high-calibre sports car. The Audi S8 races from 0 to 100 km/h in 5.1
seconds. The speed is not governed electronically until the needle
reaches 250 km/h. The engine shows a distinctly modest thirst,
needing only 13.9 litres of fuel per 100 kilometres – a figure
achieved partly thanks to the consistent use of lightweight design,
which clearly sets the A8 range apart from its competitors. With its
innovative aluminium body, the Audi Space Frame ASF, the S8 weighs
just 1940 kilograms, including the dynamic, sure-footed quattro
drive. On the new Audi S8, every horsepower has to propel just 4.31
kilograms – the power-to-weight ratio of a sports car.

Drivetrain: Even more
dynamism

Typically for an Audi,
the new S8 likewise focuses on quattro permanent four-wheel drive.
As a result it produces superior traction in all surface conditions.
25 years of expertise acquired in this domain by the brand with the
four-ring emblem have led to the development of a new quattro
generation with asymmetric/dynamic torque distribution – further
evidence of Audi's philosophy of "Vorsprung durch Technik".

A centre differential, installed longitudinally in the driveline,
distributes power between the front and rear wheels according to the
prevailing situation. Normally, 40 percent is routed to the front
wheels and 60 percent to the rear, this slight emphasis on the rear
underlining the dynamic character of the Audi S8. If the surface
conditions change, the purely mechanical differential responds
without any delay; it can divert up to 85 percent of power to the
rear wheels, and as much as 65 percent to the front wheels. If a
wheel on one axle spins, it moreover overrides the Electronic
Differential Lock EDL by applying the brakes.

The new S8 is equipped with six-speed tiptronic as standard. In
keeping with the character of this saloon model, the final ratio of
the automatic transmission is lower than on the A8 – the saloon is
still capable of forceful acceleration even in sixth gear. The
electronic transmission control is optimised to change gear more
dynamically. The driver can call up the transmission's Sport mode
via the selector lever – it still performs upshifts even at
relatively high engine speeds. It is in addition possible to change
gear manually with the shift paddles located behind the steering
wheel.

For Audi, lightweight design is a philosophy that has implications
for every area of a vehicle. The V10 in the Audi S8 weighs in at a
mere 220 kilograms, in other words 20 kg less than an equivalent
competitor engine. Good axle load distribution and impressive road
behaviour are the result. For the same reason, the batteries and the
energy management are housed in the luggage compartment.

Chassis: Built for serene
speed

The basic version of the
Audi A8, adaptive air suspension, already possesses distinctly
sporty attributes thanks to its elaborate layout. The control arms
are made from aluminium; the front suspension consists of a
four-link structure, and there is self-tracking trapezoidal-link
rear suspension. Various details of this layout were revised on the
S8.

The basis is "adaptive air suspension sport", the sports suspension
layout that is available for the A8 as an option. On the S8, the
characteristics of the air springs and the shock absorbers
integrated into the air-spring bellows have been made somewhat
firmer. With a further reduction in rolling and pitching movements,
the sporty top model behaves with even greater agility and
manoeuvrability, but is as stable and safe as ever. The
elastokinematics of the rubber mounts in the axles have likewise
been modified in keeping with the character of the S8. The variable
steering ratio is roughly ten percent more direct, for even more
spontaneous handling.

Drawing information from seven special sensors and a number of other
parameters, the damping responds adaptively to the prevailing
requirements in a fraction of a second. Its control system features
four driving modes – automatic, comfort, dynamic and lift – which
the driver can call up via the terminal of the MMI operating system.
The body's ride height is as envisaged in conjunction with adaptive
air suspension sport, which is already 20 mm lower than standard. On
the S8, ground clearance is varied in three stages between 125 mm in
the comfort mode and 95 mm at constant high motorway speeds.

The Audi S8 is equipped ex works with S-design cast alloy wheels.
Their dimension is 9J x 20, and the wide tyres are size 265/35. An
18-inch brake system assures a superlative braking performance. It
features four large-size ventilated brake discs. The brake calipers
are painted black, and adorned with a titanium grey S8 badge at the
front. The discs on the front wheels measure 385 millimetres in
diameter, and 335 mm at the rear.

The optional ceramic brakes that also became available for the
twelve-cylinder A8 in summer 2005 are a further special feature of
the S8. They are made from a composite material comprising
high-strength carbon fibres embedded in hard, frictionally resistant
silicon carbide. The ceramic discs offer significant advantages
compared with conventional steel discs. They are about half the
weight, are largely insusceptible to heat fading and corrosion, and
achieve an operating distance of up to 300,000 kilometres – four
times that of steel discs. Optically, the high-tech brake system can
be identified by the special perforation on the large-size discs and
the anthracite-coloured calipers with the "Audi ceramic" lettering.

Design: Discreet sports
style

The models in Audi's S
range have always epitomised refined sports appeal. The same applies
to the S8 – it lends the design of the A8 a dynamic edge. This
representative saloon is already inherently light and elegant in
character – its aesthetic appeal reflects its exceptional position
as a sports model in the luxury class.

The S8, too, is supremely athletic yet never aggressive in outlook.
The most striking differences are to be found at its front end. The
eye-catching single-frame grille displaying the S8 emblem is in
platinum grey, and its vertical struts have a chrome finish. Beneath
the grille, there are three low air inlets cut into the front apron.
The two large air inlets beneath the headlights are filled with
honeycomb grilles.

Down the sides, in addition to the 20-inch wheels and the special
brakes, three details hint at the potential of the V10 engine:
emblems on the wheel arches, door handles with aluminium strips and
the aluminium-look exterior mirror housings. At the rear, the S8
emblem, a spoiler integrated into the luggage compartment lid, a
subtle light edge in the apron and an exhaust system with four
ellipsoidal tailpipes complete the range of optical modifications.
The S8 is the only model in the A8 range to be available in the
exclusive colour Daytona Grey, pearl effect.

Interior: Attention to
detail

In common with the
exterior, the interior design of the Audi A8 reflects a character of
dynamic elegance and high quality – from the supple flow of the
driving area to the MMI user interface (Multi Media Interface),
which remains unequalled by any competitor thanks to its logical,
intuitive operating principle.

The S8 adds various specific accents to this luxurious interior.
This is the first time that bi-colour seats with seams in a
contrasting colour have been used as standard; their four colour
combinations emphasise the air of luxurious sports appeal. The
colours for the seat centre sections differ from those for the side
sections and head restraints. The headlining is additionally
available in the S models' signature colour silver.

Further details of the interior distinguish the sporty top model
from the A8. The door sill trims are adorned with S8 emblems, and
the inlays are in brushed aluminium or alternatively carbon fibre.
The three-spoke leather multifunction sports steering wheel with the
S emblem features colour-contrasting seams and aluminium-look shift
paddles. Leather and aluminium are used on the selector lever knob.
The needles on the instrument dials are in white, their scales in
light grey and their values in the characteristic S italic script.

Safety: No compromises

Quattro drive is one of
the core areas of expertise of the brand with the four-ring emblem.
It gives Audi drivers decisively more safety by always assuring
optimum traction. The asymmetric/dynamic torque split that is
possible on the new Audi S8 builds on this already significant
advantage. The high-performance brake system, too, makes a
substantial contribution towards active safety. The S8 is equipped
with a dynamic stability system that can be deactivated if required.
Its control strategy is tailored specifically to the dynamics of the
S8.

In common with all other Audi A8 models, the S8 sporty top model
comes complete with a package of restraint systems that are
perfectly matched to the highly rigid aluminium body. The package
includes two front airbags, four side airbags and large-area
sideguard head airbags. All five three-point belts in the Audi S8
are fitted with belt tensioners. Active head restraints for the
front seats reduce the risk of whiplash injuries in the event of a
rear-end collision.

The innovative lighting technology adaptive light with LED daytime
running lights is standard equipment on every Audi S8. Here, the
xenon plus headlights are equipped with static turning lights and
dynamic cornering lights. The separate LED daytime running lights,
each of which consists of five white light-emitting diodes and
consumes only a minimal amount of energy, can be considered a
pioneering invention.

Equipment: Luxury with new
accents

The Audi A8 is already a
luxuriously equipped saloon. It features for instance deluxe
automatic air conditioning, the MMI operating system, the Driver
Information System, the electromechanical parking brake complete
with starting assist function, air suspension, the exclusive audio
system and the electrically adjustable front seats.

The Audi S8 extends this package with a whole array of other
standard features. In addition to adaptive light technology, the
special 20-inch wheels and the 18 inch brake system, it incorporates
further luxury features in the version for the German market:
advanced key, the keyless access and authorisation system including
starter button for the V10, sound-insulating double glazing for the
windows, heated front and rear seats, a navigation system with DVD
drive and a surround audio system with CD changer. The door armrest
and the centre console in the S8 are upholstered in leather,
together with the seats. The sports seats are equipped with lumbar
supports and a memory function.

One particular highlight that is available as an option is the
Advanced Sound System from Bang & Olufsen. The fully digital system
from the Danish high-end manufacturer integrates 14 speakers, each
energised by its own output stage. The output stages are grouped
together in two amplifiers, which supply an output of 1100 Watts if
required. The front tweeters use what is known as Acoustic Lens
Technology, and act as perfect punctiform sound sources. This sound
system represents the state of the art in audio reproduction adding
special allure to the sporty, deluxe equipment of the Audi S8.